The development of wearable electronics and wire-less network devices bring the dramatic growth of Internet of Thing (IoT) chips. Currently, the IoT chips are often equipped in the environment with power supply. On the contrary, the IoT chips equipped in the environments with no power supply, such as outdoor emergency protective systems, outdoor temperature regulation systems, indoor real-time medical systems and indoor logistic systems, will become the mainstream of IoT chips in the future. However, there are three inevitable issues emerging. The first one is long signal/energy transport and high power loss. The second one is the energy harvesting of indoor light, and the last one is the application in glass and flexible substrates.
FIG. 1 is a schematic view of a conventional two-dimensional self-powered chip. A self-powered device based on the circuit board 91 combines the light energy harvesting element A, such as solar cells, etc., and the other functional elements B, C, D . . . and so on, which are electrically connected to each other. Wherein, the light energy harvesting element A collects and converts light energy into electricity, and the electricity is transmitted through the power transmission point A1 signal to the energy signal receiving point C1, and thus is capable of supplying power for the operations of functional elements B, C, D . . . (may include such as an IoT chip) etc. Due to the two-dimensional configuration on circuit boards in the conventional methods, the energy transfer distance H will be up to at least a few millimeters or more, which is not only unfavorable to the downsizing of elements, but also bearing to the energy loss during transferring and other issues.
In addition, most traditional environmental energy harvesting devices are monocrystalline silicon/polycrystalline silicon-based solar cells, which can provide high photoelectric conversion efficiency (16-20%), but require the use of silicon substrates, with thicknesses of 220˜250 μm, as the absorption layer. The three-dimensional heterogeneous vertical integration is inapplicable. Furthermore, the energy harvesting capacities of silicon solar cells for indoor lights are lower than those of the amorphous silicon solar cells.